*: use latest ffmpeg-sys using bindgen

* Update bindings to newest ffmpeg version for new ffmpeg-sys, which is mostly generated by bindgen
* Bring back removed feature flags
* Fix whitespace formating
* Remove prepended enum names to enum variants
* Remove unneeded allows

src/device/extensions.rs

@@ -26,7 +26,7 @@ impl<'a> DeviceIter<'a> {
 	pub unsafe fn wrap(ctx: *const AVFormatContext) -> Result<Self, Error> {
 		let mut ptr: *mut AVDeviceInfoList = ptr::null_mut();
 
-		match avdevice_list_devices(ctx, &mut ptr) {
+		match avdevice_list_devices(ctx as *mut _, &mut ptr) {
 			n if n < 0 =>
 				Err(Error::from(n)),